Yup, just encounted the same issue, as well as fleet members on at the time too.
Looks like a game stopper bug. Was looking forward to these new Romulan missions. Looks like the new mission journey stops here.
I had this too but waiting 15 min to reset i got discoed apone relog i tryed and asked me to kill 3 of 3. for some reson it askes some people to kill 4 of 4 and those people can't finish it. its supose to be 3 of 3. if you get 4 of 4 try relogging or waiting 15 min.
OK, I did the diplomacy way a with a few different toons. With my VA Ambassador, I was able to get by with Diplomacy and also get the codes with Diplomacy, so I got that accolade. However, with another toon who is a VA, but only a 2nd level Diplomat, I was not able to get by with Diplomacy. Yet on a 3rd toon, I was able to get in with diplomacy, however I could not get the codes with diplomacy, even though this one was an ambassador too. I think the mission is bugged that way. When I went to speak with Janek I thinhk it is, I tried to be diplomatic, but after choosing the first diplomatic answer, it brought me to a window that only gave me 2 chooses. She said "Is this the way you want this to end?" I could only click on "Yes", which meant she would attack me, or click on the other one (Maybe we can work this out or whatever it says). But by clicking on the 2nd choice, it brought me back to the first window which would again bring me back to either Yes or the other one. So either way she was going to attack me again. I never had the option to finish with diplomacy with her. So that is slightly bugged.
My team I ran with a few moments ago ran into the bugged wall issue too.
We beamed out (all of us), relogged, and restarted that portion of the mission, and just ran past the guy guarding the hallway and fought the 5 mobs. Then we were able to use the plates to open the door.